This article is missing information about the history of the subject.(September 2011)
An all-way stop – also known as a four-way stop (or three-way stop etc. as appropriate) – is a traffic management system which requires vehicles on all the approaches to a road intersection to stop at the intersection before proceeding through it. Designed for use at low traffic-volume locations, the arrangement is common in the United States, Canada, South Africa, Liberia, and Mexico, as well as in a number of, usually rural, locations in Australia where visibility on the junction approaches is particularly poor. The stop signs at such intersections may be supplemented with additional plates stating the number of approaches.
In most jurisdictions of the United States, the rules of the all-way stop are the same. A motorist approaching an all-way stop is always required to come to a full stop behind the crosswalk or stop line. Pedestrians always have the priority to cross the road, even if the crosswalk is not marked with surface markings.
Driving instructors suggest that communication is always vital—including the use of turn signals to indicate which direction you intend to turn.Often, vehicles are able to make compatible moves at the same time without following the order listed above. If it is not clear who has the right-of-way, drivers should use good judgement until they clear the intersection. Within some U.S. jurisdictions, such as the state of Idaho, bicyclists are exempt from the need to make a complete stop, but must give way to other vehicles as otherwise required by law. In Australia, drivers must give way to other drivers on their right side after coming to a stop.
In the United States, the Federal Highway Administration's Manual on Uniform Traffic Control Devices (MUTCD) defines the standards commonly used for the application of all-way stops.Where a stop has been determined to qualify, it is signed at all approaches to the intersections with a standard octagonal "Stop" sign, with a supplemental "All-Way" plate. Earlier editions of the MUTCD allowed supplemental plates specifying the number of approaches in an all-way stop, as in "2-Way", "3-Way" or "4-Way". According to the MUTCD, installation of an all-way stop should be based on a traffic engineering study to determine if minimum traffic volume or safety criteria are met. These intersections are often found where roads have light-volume traffic which does not justify a traffic light.
An all-way stop may also be justified if the intersection has shown a history of collisions involving pedestrians or vehicles. All-way stops may also be used as an interim measure preceding the placement of a traffic light, to provide a low-speed area for pedestrians to cross, where a cross street experiences considerable difficulty finding safe gaps due to heavy traffic volumes, or where traffic is frequently delayed by turning conflicts. Additionally, the MUTCD advocates the placement of all-way stops at intersections between through roads in residential areas if an engineering study can show that traffic flow would be improved by installing it. Despite published guidelines, all-way stops are routinely placed by jurisdictions due to political pressure from adjacent residents.[ citation needed ] Intersections between two minor highways with similar traffic counts, two collector roads in an urban or suburban setting or a collector road and a local road in a busy setting (such as near a school) are the most common locations for an all-way stop.
Traffic signals will sometimes flash red indications in all directions following a malfunction, or all-red flashing operation may be scheduled to reduce delay or handle construction activity or unusual traffic patterns. When a traffic signal flashes in all-red mode, it legally operates as an all-way stop.When all approaches to an intersection are controlled in this way the rules for an all-way stop apply. Traffic signals may also flash yellow to major directions and flash red to minor directions during off-peak times to minimize traffic delays, in which case only side-street traffic is required to stop and yield the right of way to crossing traffic on the major street.
During electrical outages when a traffic signal does not display any indications including flashing red, some jurisdictions require that the intersection be treated as an all-way stop. Other jurisdictions treat a dark signal as an uncontrolled intersection, where standard rules of right-of-way apply without the requirement of a complete stop.
The main reason for the use of stop signs at road junctions is safety. 430 According to an international study of locations where the system is in use, all-way stop control applied to four-legged intersections may reduce accident occurrence by 45%. :431–432 However, given alternative methods of intersection control and some of the disadvantages of all-way stops, the Handbook of Road Safety Measures recommends that four-way stops are best used between minor roads away from urbanized areas. :431–433 Another benefit of all-way stops is assurance that vehicles enter the intersection at a low speed and have more time to take heed of the traffic situation, :430 especially useful when sight distance is highly restricted.:
Some of the disadvantages associated with all-way stops are:
Few countries outside North America – least of all, those in Europe – have intersections at which all users must stop at all times; the conditions for stop sign placement may indeed preclude such an arrangement in many places. 430 In Sweden all-way stops (Flervägsstopp) have been tested since the 1980s but are little used even though they are now permitted. In the UK they have always been very uncommon and were formally prohibited by the Department for Transport in 2002.:
Four-way stops are common in the Southern African Development Community area, with priority going to the first vehicle to arrive and stop at the line.
At four-legged intersections within Europe, a roundabout or mini-roundabout may be used to assign a relative priority to each approach. (Roundabouts remain rare in North America, where early failures of rotaries and traffic circles caused such designs to lose favor until the gradual introduction of the modern roundabout in the late 20th century.) Alternatively, at smaller intersections, priority to the right is widely used in most countries.
Traffic on roads consists of road users including pedestrians, ridden or herded animals, vehicles, streetcars, buses and other conveyances, either singly or together, while using the public way for purposes of travel.
A roundabout is a type of round (about) intersection or junction in which road traffic is permitted to flow in one direction around a central island, and priority is typically given to traffic already in the junction.
An intersection is an at-grade junction where two or more roads converge, diverge, meet or cross. Major intersections are often delineated by gores and may be classified by road segments, traffic controls and lane design.
A pedestrian crossing or crosswalk is a place designated for pedestrians to cross a road, street or avenue. The term "pedestrian crossing" is also used in some international treaties that pertain to road traffic and road signs, such as the Vienna Convention on Road Traffic and the Vienna Convention on Road Signs and Signals.
Traffic lights, traffic signals, stoplights or robots are signalling devices positioned at road intersections, pedestrian crossings, and other locations to control flows of traffic.
A stop sign is a traffic sign designed to notify drivers that they must come to a complete stop and make sure the intersection is safely clear of vehicles and pedestrians before continuing past the sign. In many countries, the sign is a red octagon with the word STOP, in either English or the national language of that particular country, displayed in white or yellow. The Vienna Convention on Road Signs and Signals also allows an alternative version: a red circle with a red inverted triangle with either a white or yellow background, and a black or dark blue STOP. Some counties may also use other types, such as Japan's inverted red triangle stop sign. Particular regulations regarding appearance, installation, and compliance with the signs vary by some jurisdiction.
An advanced stop line (ASL), also called advanced stop box or bike box, is a type of road marking at signalised road junctions allowing certain types of vehicle a head start when the traffic signal changes from red to green. Advanced stop lines are implemented widely in the Netherlands, Denmark, the United Kingdom, and other European countries but the idea was first conceptualized by transportation planner Michael Lynch for the city of Portland, Oregon in response to numerous bike crashes at intersections.
Road signs in Sweden are regulated in Vägmärkesförordningen, VMF (2007:90), and are to be placed 2 metres from the road with the sign 1.6 m from the base for motorized roads. Except for route numbers, there are a maximum of three signs on a pole, with the most important sign at the top. All signs have a reflective layer added on selected parts of the sign as is custom in European countries; most larger signs also have their own illumination.
A turn on red is a principle of law permitting vehicles at a traffic light showing a red signal to turn into the direction of traffic nearer to them when the way is clear, without having to wait for a green signal. It is intended to allow traffic to resume moving provided proper caution is observed; however, various studies find that it increases the risk of collisions between vehicles and pedestrians.
For driving in the United States, each state and territory has its own traffic code or rules of the road, although most of the rules of the road are similar for the purpose of uniformity, given that all states grant reciprocal driving privileges to each other's licensed drivers. There is also a "Uniform Vehicle Code" which was proposed by a private, non-profit group, based upon input by its members. The UVC was not adopted in its entirety by any state. As with uniform acts in general, some states adopted selected sections as written or with modifications, while others created their own sui generis statutes touching upon the same subject matter. As required by the federal Highway Safety Act of 1966, all states and territories have adopted substantially similar standards for the vast majority of signs, signals, and road surface markings, based upon the Manual on Uniform Traffic Control Devices from the U.S. Department of Transportation. Many of the standard rules of the road involve consistent interpretation of the standard signs, signals, and markings such as what to do when approaching a stop sign, or the driving requirements imposed by a double yellow line on the street or highway. Many agencies of the federal government have also adopted their own traffic codes for enforcement on the grounds of their respective facilities.
The use of traffic lights to control the movement of traffic differs regionally and internationally in certain respects. This article describes some of these non-universal features. Note that the color phase commonly known as "yellow" is often referred to, especially in official usage, as "amber"; for consistency this article uses "yellow" throughout.
A HAWK beacon is a traffic control device used to stop road traffic and allow pedestrians to cross safely. It is officially known as a Pedestrian Hybrid Beacon (PHB). The purpose of a HAWK beacon is to allow protected pedestrian crossings, stopping road traffic only as needed. Where standard traffic signal 'warrants' prevent the installation of standard three-color traffic signals, the HAWK beacon provides an alternative.
The normal function of traffic lights requires more than sight control and coordination to ensure that traffic and pedestrians move as smoothly, and safely as possible. A variety of different control systems are used to accomplish this, ranging from simple clockwork mechanisms to sophisticated computerized control and coordination systems that self-adjust to minimize delay to people using the junction.
In the United States, road signs are, for the most part, standardized by federal regulations, most notably in the Manual on Uniform Traffic Control Devices (MUTCD) and its companion volume the Standard Highway Signs (SHS).
Stop and yield lines are transverse road surface markings that inform drivers where they should stop or yield when approaching an intersection. In some cases stop or yield lines are used in advance of mid-block crosswalks.
Road signs in Canada may conform to the Manual of Uniform Traffic Control Devices for Canada (MUTCDC) by the Transportation Association of Canada (TAC) for use by Canadian jurisdictions. Although it serves a similar role to the MUTCD from the US Federal Highway Administration, it has been independently developed and has a number of key differences with its American counterpart, most notably the inclusion of bilingual (English/French) signage for jurisdictions such as New Brunswick with significant anglophone and francophone population, and a heavier reliance on symbols rather than text legends.
Terminology related to road transport—the transport of passengers or goods on paved routes between places—is diverse, with variation between dialects of English. There may also be regional differences within a single country, and some terms differ based on the side of the road traffic drives on. This glossary is an alphabetical listing of road transport terms.
Road signs in Mongolia are similar to the Russian road sign system. They ensure that transport vehicles move safely and in an orderly manner, and inform the participants of traffic built-in graphic icons. These icons are governed by the Vienna Convention on Road Traffic and Vienna Convention on Road Signs and Signals.
Road signs in the Philippines are regulated and standardized by the Department of Public Works and Highways (DPWH). Most of the signs reflects minor influences from American and Australian signs, but keeps close to the Vienna Convention on Road Signs and Signals as an original signatory.
Road signs in Russia ensure that transport vehicles move safely and orderly, as well as to inform the participants of traffic built-in graphic icons. These icons are governed by the Vienna Convention on Road Traffic and Vienna Convention on Road Signs and Signals.